Abstract：
Emerging evidence indicates that androgen receptor (AR) signaling plays a critical role in the pathogenesis of male-dominant urothelial cancer. Meanwhile, latrophilins (LPHNs), a group of the G-protein-coupled receptor to which a spider venom latrotoxin is known to bind, remain largely uncharacterized in neoplastic diseases. The present study aimed to determine the functional role of LPHN3 (encoded by the ADGRL3 gene), in association with AR signaling, in urothelial tumorigenesis. In human normal urothelial SVHUC cells, AR overexpression and androgen treatment considerably increased the expression levels of ADGRL3/LPHN3, while chromatin immunoprecipitation assay revealed the binding of AR to the promoter region of ADGRL3. In SVHUC or SVHUC-AR cells with exposure to a chemical carcinogen 3-methylcholanthrene, LPHN3 activation via ligand (e.g., α-latrotoxin, FLRT3) treatment during the process of the neoplastic/malignant transformation or LPHN3 knockdown via shRNA virus infection induced or reduced, respectively, the oncogenic activity. In N-butyl-N-(4-hydroxybutyl)nitrosamine-treated female mice, α-latrotoxin or FLRT3 injection accelerated the development of bladder tumors. Immunohistochemistry in surgical specimens further showed the significantly elevated expression of LPHN3 in non-muscle-invasive bladder tumors, compared with adjacent normal urothelial tissues, which was associated with a marginally (p = 0.051) higher risk of disease recurrence after transurethral resection. In addition, positivity of LPHN3 and AR in these tumors was strongly correlated. These findings indicate that LPHN3 functions as a downstream effector of AR and promotes urothelial tumorigenesis.
摘要：
新的证据表明，雄激素受体（AR）信号在男性显性尿路上皮癌的发病机理中起着至关重要的作用。同时,latrophilins(LPHN)，一组已知与蜘蛛毒latrotoxin结合的G蛋白偶联受体，在肿瘤性疾病中仍然基本上没有特征。本研究旨在确定LPHN3（由ADGRL3基因编码）的功能作用，与AR信号相关，在尿路上皮肿瘤发生中。在人类正常尿路上皮SVHUC细胞中，AR过表达和雄激素处理显着增加了ADGRL3/LPHN3的表达水平，而染色质免疫沉淀分析显示AR与ADGRL3的启动子区域结合。在SVHUC或SVHUC-AR细胞中，暴露于化学致癌物3-甲基胆碱，通过配体激活LPHN3(例如，α-latrotoxin,FLRT3）在通过shRNA病毒感染诱导或减少的肿瘤/恶性转化或LPHN3敲低的过程中进行治疗，分别,致癌活性。在N-丁基-N-（4-羟丁基）亚硝胺处理的雌性小鼠中，α-latrotoxin或FLRT3注射加速膀胱肿瘤的发展。手术标本中的免疫组织化学进一步显示，在非肌肉浸润性膀胱肿瘤中LPHN3的表达显着升高，与邻近的正常尿路上皮组织相比，这与经尿道切除术后疾病复发的风险稍高(p=0.051)相关。此外,LPHN3和AR在这些肿瘤中的阳性具有很强的相关性.这些发现表明LPHN3作为AR的下游效应物发挥作用并促进尿路上皮肿瘤发生。
